1. Field of the Invention
This invention relates, in general, to an improvement to an air induction control device for an internal combustion engine, and more particularly to an air induction control device which modifies the air/fuel mixture in the combustion chamber by controlling the intake vacuum in the engine intake passageway within a desirable range.
2. Description of the Prior Art
During deceleration of an Internal Combustion ("IC") engine the throttle valve in the intake passageway is fully closed despite high engine speed, and accordingly, the intake vacuum downstream of the throttle valve is excessively increased. As a result, several undesirable results may occur. By way of example, engine oil sucked into the combustion chambers of the engine by the action of the increased intake vacuum can cause an increase in the amount of oil burning. Additionally, the fuel lining the intake passage is vaporized, temporarily rendering the fuel/air ratio in the combustion chamber overly rich which can result in stalling and other engine malfunction.
An illustration of another problem associated with deceleration or periods of idle, when the vacuum in the engine is at its maximum, is that the standard carburetors used in internal combustion engines have a venturi whereby the high speed of air drawn into the engine suctions up fuel. When the vacuum in the intake manifold becomes great, the amount of fuel consumed increases, thus decreasing the efficiency of the engine.
Since the earliest internal combustion engines, there has been a search for a method to provide the intake manifold with an optimal mixture of air to fuel, in order to ensure maximum efficiency.
Air induction control valves have heretofore generally been restricted to those intended to prevent extreme vacuum conditions from developing in the combustion chamber during periods of deceleration. Fukuhara, U.S. Pat. No. 4,237,842, discloses such a spring valve that is in communication with the air upstream from the throttle and the air passage downstream through two external tubes. When the intake vacuum exceeds a predetermined level in the downstream valve tube, a valve member is moved against the force of the coil spring toward the stopper and accordingly separates from the valve seat allowing air to enter. Conversely, the valve closes when the intake vacuum in the downstream tube rises above the predetermined level to allow the biasing force of the spring to push the valve member back against the valve seat so as to block communication between the upstream and downstream sides of the valve.
Dorsic, U.S. Pat. No. 4,303,047, shows a method for controlling the vacuum in an engine through a bypass that contains a valve that responds to the differential in pressure between the downstream side of a butterfly valve and the atmosphere. This butterfly valve is downstream of and mechanically connected in a normal position to the carburetor throttle valve.
Morita, U.S. Pat. No. 4,434,778, discloses a valve set in an air passage communicating with the upstream and downstream sides of a throttle valve. When the valve is open the air passes through the valve from the air filter to the air passageway downstream of the throttle valve. A spring in the valve is activated by a diaphragm member which positions the valve body in an open or closed position. The diaphragm consists of two chambers, one of which is in direct communication with the downstream air passage and directly affected by the engine vacuum level, the other of which is in communication with the first chamber through a bellows to which the spring and valve stem are attached.
In early aeronautical IC engines, optional air/fuel mixture was achieved through a manual control of the mixture in which the amount of air is controlled and the variations are made by observation of the temperature variations in the cylinders through the use of appropriate instruments: the temperature indicator in the cylinder heads or an EGT and EET.
In later IC engines, a servo mechanism was added that operated on the basis of engine temperature variations. The servo would close the air intake to the engine to a greater or lesser degree in order to achieve stability through the incorporation of controlled cooling fins. In this way the temperature would be stabilized, and a consistent air intake flow can be maintained.
The devices described above provide some advantages in operation, namely, preventing excessive vacuum formation during declaration. Nevertheless, none of these devices uses a flow restriction element that comprises calibrated openings to effect an increase in fuel efficiency under all operating conditions.
Additionally, none of these devices attempts to polarize oxygen molecules entering the induction control valve to effect more efficient molecular bonding of fuel and air, thus resulting in maximal fuel efficiency in an internal combustion engine.